[CR]Re: Debunking time again


Example: Racing

Date: Thu, 30 May 2002 10:21:04 -0700 (PDT)
From: Tom Dalton <tom_s_dalton@yahoo.com>
To: classicrendezvous@bikelist.org
In-Reply-To: <141.f3506bb.2a27b034@aol.com>
Subject: [CR]Re: Debunking time again

The Bohemian Bicycles website contains Scot Nichol's 6-part series about frame materials. It is somewhat general, but quite informative. It don't know a lot about materials science, but I did take one undergraduate course and Nichol's information was consistent with what I learned in that class. I think what Steven is driving at is that the mechanical properties of a steel tube that would influence ride (not durability, not yield strength) depend primarily on the geometry of the tube (wall thickness, diameter, and subtler aspects of material distribution dictated by tapers and butting). The density of steels is essentially constant as is the elastic modulus, therefore "stiffness" and weight should not change with different alloys, assuming the tubes are dimensionally identical. The catch is that a carbon steel bike would be pretty frail if the tubes were thin-walled and oversized. It would be light and stiff, but a collision with a pothole may exceed it's yield strength. The above is consistent with what they teach you in school, in the real world of frame building things may be different, at least in subtle ways. Personally I've never ridden two frames of differing materials that were otherwise similar enough to provide adequate control to assess the "feel" of different alloys and heat treatments... but based on what I've read, I doubt I'd feel a difference. Of course alloys still matter for other reasons, otherwise they wouldn't exist. Taken to the exteme, suggesting otherwise implies that steel companies "invent" special, expensive materials to screw consumers, when plain carbon steel would serve all purposes adequately. This assumes that consumers, including engineers spec'ing steels for bike tubes, turbine blades, surgical instruments, etc. are universally idiotic. Hey, I'm no lover of engineers, but I'll conceed that this is not the case. Tom Dalton, with apologies to engineers, in Bethlehem, PA NortonMarg@aol.com wrote: In a message dated 5/30/02 7:07:19 AM Pacific Daylight Time, monkeylad@mac.com writes:

<< I'm sure most people will chime in that I'm just full of it. Before you react look for the article in Bicycle Guide and look at the materials used in bike construction 40 years ago. Also note that we're talking about ride and not weight, longevity, ETC. . . Like everyone I want to believe that it really does matter since I'm paying extra for quality tubing, but when it comes to ride it just doesn't matter. I'm now off to put on my asbestos underwear. >>

Have to disagree. Magazines publish articles to fill space and sell magazines. I've said this before and I'll say it again, Albert Eisentraut was one of the first American builders to vary the tubing gauges in a frame, not just using the standard "tube set". It made a HUGE difference in ride quality and a minuscule difference in weight. If what you are saying is that you can get a similar ride quality from cheap tubing (with a weight penalty), that's a somewhat fair statement. However, the cheaper, heavier steel tubing doesn't allow the artistic and talented frame builder to design in the subtleties that varying the best quality of tubes allows. Your statement would be fully true if subtlety did not exist in the universe. The smartest article I remember reading on the subject had to do with telling riders it's not the "steel" that matters, it's the "tubing". Tube configuration, wall thickness, taper, etc. matters more to a finished frame than "what steel is it?" Caeterus paribas, assuming first class workmanship.
Stevan Thomas
Alameda, CA